Mold for casting insulators



Decl 15, 1925- M. HUNT MOLD FOR CASTING INSULATORS JMW Mdr; den hf Hun1i WW ATTORNEY M. H. HUNT MOLD FOR CASTING INSULATORS Dec; 15 1925. l1,565,460

Filed OGL 11, 192:5 2 Sheets-Sheet 2 mvENToR Marsden HHU/v A'iORNEYwlNEssEs: 5

Patented Dec. 15, 1925.

UNITED STATES l 1,565,460 PATENT OFFICE.

MARSDEN H. HUNT, F OAKLAND, CALIFORNIA. ASSIGNOR TO WESTINGHOUSE ELEC-TRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

MOLD FOR CASTING INSULATORS.

Application filed Octobenll, 1923. vSerial No. 667,881.

To all whomz't may concern:

Be it known that I', MARsDnN H. HUNT, a citizen of the United States,and a residentof Oakland, in the county of Alameda and State ofCalifornia, have invented a new and useful Improvement in Molds forlCasting Insulators, of which the following is a specification. i

My invention relates to strain insulators of the class knownas link,strain insulators and more particularly to a mold for making suchinsulators in a single operation.

The objects of my invention are to provide a mold for such an insulatorwhich shall l form the sa'me in a single operation, which shall. at thesame time, form passages or openings in the body thereof and shall'afford an inexpensive, efficient and convenient means of producinginsulators of this class b v molding. l

Insulators have been cast heretofore, but there has not been found, inthe .prior art, a means of forming apertures or openings through thebody of the insulator during i the process of casting the insulatorbody. To produce such openings it has been found necessary to cut thesame through the insulatoirbody by a special cutting tool, while theinsulator was in a plastic state and this l necessitated va separatehandling and operation apart 'from the casting. There resulted from thiscutting considerable loss because of breakage of the insulators. By theuse of my mold I 'am enabled to overcome the difficulties of the priorart and to produce by casting, a much stronger and more uniforminsulator, at a less cost and with less handling thanheretofore.

My invention consists, substantially, in the provision of a mold, havinga base and a plurality of sides co-operating therewith, which areprovided with core members of such conformation that when the parts ofthe mold are assembled and a clay suspension cast therein they will notonlyy form the body portion of the insulator of the desired shape butwill, at the same time, form therein the apertures or openings desired.The sides may be readily and separately removed kand disassembled frolnthe basel and insulator leaving the latter in its required plastic form.

Referring to `the accompanying drawings constituting a part hereof andinwhich like reference characters indicate like parts,

Figure 1 is a horizontal sectional view of my mold, taken along lineI--I of Fig. 2;

Fig. 2 is a side elevational view thereof showing one of the sides ofthemold removed;

Fig. 3 is a vertical sectional view taken along line 111-111 of Fig. 2,looking in the direction of the arrows;

Fig. 4 is a sectional view of the base of mymold with the sides and-topof the mold removed therefrom showing an insulator supported thereon;

Fig. 5 is an elevational view of one of'a pair of complementary sidesand core members of my mold; and l Fig. 6`is an elevational view of oneof the other pair of complementary` sides and core inembersof my mold.

Referring more particularly to the drawings. the mold consists of a base1 which, 75 in the form illustrated here, is provided with a centralelevated portion 2, which is adapted to position. the respective sideand top members constituting the body of the mold, on the base 1.

Oppositely positioned on the base 1 is a pair of sides' 3 and 4 whichcarry, preferably, integrally therewith, core members 5 and 6respectively projecting from their inner faces and meeting`approximately over the center line of the base. Tgvo otheropvpositelypositioned sides 7 and 8 are mounted on the base 1 in(zo-operative relation therewith and with the sides 3 and 4. The. sides7 and 8 are provided with extended top portions 9 and 10, respectively,which meet lapproximately over the central axis of the base 1 andprovide a top for my mold.

The side members 7 and 8 are provided /with core members 11 and 12,respectively, 95

preferably integral therewith, which extend from the inner faces of saidsides and meet approximately at the vertical centralvaxis of the base,similarly to the core members 5 and 6 but in `a different horizontalplane,` and at 109 right angles thereto. `'I-hetop formed by members 9and 10, is, at the central portion thereof, provided with an aperture 13through which the plastic material, .such as clay in suspension of whichmy insulator may 4be made, may be poured or otherwise introduced intothe body of the mold. i

The base 1 is provided with a, dished-out or insert portion 14 near thecenter of its upper surface and there is furtherprovided in this(lished-out poi'tiolninsets or recesses 15l :ind 16 adapted to form feetor lugs upon one face of the insulator. The top portions 9 and 10 of thesides 7 and 8 are likewise, near the extremities that meet over thecentral portion of the mold, dished out or recessed so as to give thedesired formation to the opposite face of the insulator when cast. f.

My mold is preferably made of plaster Paris, but any substance havingthe desired porosity, tensile strength and absorptive power may besubstituted therefor.

In casting an insulator with my improved mold the sides are:coi-operatively assembled upon the base 1, so thatsides of similar ordesired conformation shall be properly placed, in this case oppositely.They are then securely bound together by any suitable holding means, sothat they will not move or accidentally become disassembled during thecasting operation.

A plastic or semi-liquid substance, preferably clay or a clay-like bodyin suspension in water, of a constituency such that. the mass will weighapproximatelyt) ounces per quart, may be then poured or otherwiseintroduced into the mold, through the opening 13, until the mold issubstantially filled. The mold is then allowed to stand for a shortperiod, suiicient to permit the water.

of the solution to be absorbed by the body of the mold and to effect theresultant semidryingand depositing of the suspended material Within themold. More materialiis introduced into the mold and is permitted todeposit its suspended material within the mold. This is repeatedsuccessively until the mold is completely filled with the depositedsubstance and the insulator is then and thereby formed.

The sides and top of the mold, being separately removable from the base,are then withdrawn from the molded insulator and the same is in the formshown in Fig. 4, resting upon the base of the mold with the surfacecontour and openings therein complete. The insulator is then removedfrom the base and is air-dried at a temperature increasing from normalto about 100 C. This drying is continued for several days. The insulatoris then glazed by dipping in a glazing solution and is fired at a hightemperature for approximatelythree days, the

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firing temperature rising to approximately 24500 Fahrenheit. Theinsulator is then gradually cooled in the k ln for approximately threedays. The fi ing of the insulator progresses in such manner that therise of temperature to 2450o Fahrenheit is muc-h more sudden than thedecrease of temperature to normal during the cooling process. After thecooling process the insulator is ready for use.

The recesses or insets 1,5 and 16 (Fig. 4) form feet on one side of theinsulator upon which it is found desirable to permit it to stand or restduring the drying, firing and cooling steps of the process oflnanufacture.

It will be seen from the foregoing that I have provided a mold forinsulators of this character which is very convenient and eficient inoperation, may be easily assembled .and disassembled, which is ofinexpensive durable and simple construction and by which I 4am enabledto form an insulator having openings therein by a minimum number ofoperations without drilling o r cutting. My improved mold will so formAinsulators of this type that internal strains resulting from theirdrying willnot produce surface or internal cracks therein and it mayhave other advantages and results not herein specifically set forth, butwhich may be obvious from the drawings and the accompanyingspecification.

AlthoughI have particularly described and claimed the invention herein,I do not stood that, although I have illustrated this shape of core tocorrespond with this shape of insulator, yet my mold may be providedwith core members which will vary according as the Shape or contour ofthe insulator -desired to be molded is varied.-

portions disposed in crossed spaced relation to form the interlinkedopenings thereofI and constructed for withdrawal from the insulatorsthat are molded therein.

2. A mold for forming insulators of the link type comprising a structurehaving core portions disposed in crossed spaced relation to form theinterlinked openings thereof, i

said structure alsobeing constructed to provide resting-base portions onthe insulators and to permit the withdrawal of the structure from theinsulators that are molded therein.V i. v

3. A mold for forming insulators of the link type comprising a structurehaving portions conforming to the ends of the insulators and corelportions disposed in crossed spaced relation to each other, and inspaced relation to said end portions to form the interlinked openings ofthe insulators.

4. A mold for forming insulators of ther rable members having coreportionsdisposed in crossed spaced relation and shaped to form theinterlinked openings of the inSulators.

5. A mold for orming'insulators of the link type comprising a pair ofoppositelydisposed members each having a core-portion projecting towardthe core-portion of the other to form a portion of one opening of theinsulator, and a second pair of similarly disposed members each having acoreportion projecting toward the core-portion of the other in spacedsubstantially rightvangular relation to the coreportions of said firstpair of members to form a portion ofv the other opening of theinsulator.

6. A mold for forming an insulator of the link type comprising a pair ofoppositely-disposed members each having a projecting coreportionco-operating with the core portion of the other to form a substantiallysolid bridge between themembers conforming to one opening of theinsulator and a similarly shaped and related pair of members co-operating with said first pair to form the other opening of the insulator.

7. A mold for forming an insulator of the link type comprising astructure including an end portion having a portion conforming to oneend portion of the insulator, a. pair of members each having aprojecting core portion co-operating with the core por' -tion of theother to form one opening of the insulator, a pair of members similarlyprovided With core portions in crossed spaced relation to the coreportions of the first pair to form the other opening of the insulator,and an end portion having a portion com forming to aportion of the otherend of the insulator.

8. A mold for forming an insulator of the link type comprising astructure including an end portion having a portion conforming to oneend portion of the insulator, a pair of members each having a projectingcore portion co-operating with the core portion of the other to form oneopening of the insulator, a pair of members similarly provided With coreportions in crossed spaced relation to the core portions of the firstpair to form the other opening of the insulator, and an end portionhaving a portion conforming to a portion of the other end of theinsulator, one of said end portions 7core of the mold structure beingalso formed to provide a resting support portion on the insulator. A

9. A mold for forming an insulator of the link type comprising a basemember having a portion conforming to one end portion of the insulator,a pair of members each having a projecting core portion co-operatingWith the core portion of the other to form one opening of the insulator,and a pair of members similarly provided with corev portions in crossedspaced relation to the core portions of the first pair to form the otheropening of the insulator, said second pair of members each also having aportion co-operating with the other to form a portion of the other endof the insulator.

10. A mold for forming -an insulator of the link type comprising a basemember having a portion conforming to one end portion of the insulator,a pair of members fitted to said base member and each having aprojecting core portion co-operating With the core portion of the otherto form one opening ofthe insulator, and a second pair of memberssimilarly fitted to the base member and provided with core portions incrossed -spaced relation to the core portion of the first pair to formthe other opening of the insulator, said second pair of members eachalso having a portion co-operating With the other to form a portion ofthe other end of the insulator.

11. A mold for forming an insulator of the link type comprising a baseblock having a raised top portion providing a perimetral shoulder andconforming to one end of the insulator, a pair of oppositely-disposedside membels having shoulders for co-operation with the shoulders of theblock and co-operating core portions for forming an upper opening 1n theinsulator, and a second pair of oppositely-disposed side members havingshoulders for co-operationwith the shoulders of the block andco-operating ortions in spaced crossed relation to said rst coreportions for forming a lower opening in the insulator, said latter sidemembers also having co-operating top portions conforming to the otherend of the insulator.

In testimony whereof, I have hereunto subscribed my name this 22nd dayof September, 1923.

' MARSDEN H. HUNT.

